1. Field of the Invention:
The invention relates to a method for applying control data for one (or more) motor vehicle control unit(s) which contain(s) a nonvolatile memory, in particular a flash memory, for storing the control data. In this context, xe2x80x9capplyingxe2x80x9d is understood to be matching, coordinating and/or updating control data that affect the current operation of the associated motor vehicle control unit. The data can be applied, by way of example, according to the respective control unit type, motor vehicle type or current operating response of the motor vehicle component which is to be controlled, for example an engine transmission system, in order thereby to optimize the operating response of the controlled motor vehicle component and hence of the entire motor vehicle.
It has recently been possible to identify the trend of increasingly replacing electronic control units provided independently (standalone control units) with integrated mechatronic units in which mechanical components (for example sensors and actuators on a plastic support and also electrical connecting elements) are provided in addition to the electronic domain (for example a transmission electronics circuit based on a substrate made of ceramic, for example). Such mechatronic control units can be used, for example, for engine control, transmission control, anti-lock brake system (ABS) control and the like. The invention relates both to such mechatronic control units and to purely electronic control units. On a general basis, the physical space available in control units is usually limited, which results in that the electronic components need to be of compact construction.
For applying motor vehicle functions, a nonvolatile memory usually contains parameters, characteristic curves and families of characteristic curves. In application methods already proposed, the data to be applied (application data), that is to say the operating data which are to be coordinated, can be changed only offline, and not online, which makes rapid application optimized on the basis of the operating state, for example, more difficult. In this case, the applied, that is to say changed, data can be activated, i.e. loaded into the flash memory, only by a complete programming operation. Although the advantage arises that data can be applied using mass-produced control units without modification, considerable time delays and complex handling are involved in practice, which results in that this method is not very efficient.
Alternatively, data can be applied using specific application units in which the data area of the flash memory provided for the operating data that are to be applied is replaced with a random access memory (RAM). This procedure permits all application data to be rapidly changed as desired, but requires control units specifically modified for the purpose. Therefore, the data can no longer be applied using mass-produced control units. Another alternative worth considering may be to apply data in accordance with the master/slave concept, where only the essential input/output functions run on the target control unit (slave). The main unit (master) handles all the functional software. In addition, the master unit holds all the application data, which can be configured to be changeable as desired for the purposes of application. In this case too, data can no longer be applied using mass-produced control units. Furthermore, it is also necessary to ensure that the timing and functional response is identical to that of the master/slave configuration when the entire scope of functions is transferred to the target control unit.
It is accordingly an object of the invention to provide a method for applying control data for an electronic motor vehicle control unit which overcomes the above-mentioned disadvantages of the prior art methods of this general type, which permits data to be applied rapidly without the need for specific application units.
With the foregoing and other objects in view there is provided, in accordance with the invention, a method for applying/updating control data for an electronic motor vehicle control unit. The method includes the step of storing control data records in a first memory area of a nonvolatile memory. The control data records relate to a motor vehicle component which is to be controlled and/or a motor vehicle type. A control data record of the control data records is copied to a second memory area of the nonvolatile memory in order to apply/update the control data record. A section of the control data record stored in the second memory area is stored in a further memory. The section of the control data record stored in the further memory is accessed, and the control data of the section of the control data record which is to be applied is updated resulting in updated control data. The updated control data is to be used for controlling the motor vehicle component that is to be controlled. The updated control data is written back to the second memory area resulting in an updated control data record.
The method according to the invention permits efficient application for mass-produced control units, that is to say control units which are produced in large numbers for actual operational control and are not configured for a specific form of application. Such control units need not be modified, that is to say neither an additional RAM nor a ROM emulation by a RAM etc. is required. In addition, online application in the motor vehicle is possible, in which case, by way of example, the data in the RAM are coordinated (applied) during the journey. However, there is additionally the option of offline application as well, for example on the laboratory bench. Furthermore, data can be applied (coordinated or updated) quickly, since there is no need for any type of unit change or intervention in a unit.
The invention therefore provides a very efficient system configuration for motor vehicle control, for example an integrated transmission control. The invention can also be used, in particular, in control units that have a very limited memory size and, by way of example, are based on a microcontroller configuration. This permits the use of (purely electronic or mechatronic) control units which operate simply and efficiently, are economical, have a low space requirement and are distinguished by high quality and reliability. However, the invention permits not only the use of such control units having microcontrollers and integrated memory configurations but also, specifically configured control units can be used in addition to mass-produced control units.
The invention permits the use of control units based on a microcontroller configuration with efficient utilization of memory resources, without the need for any changes to the hardware structure. Furthermore, no dedicated application units are required. The total memory space requirement for the application is very low since only a relatively small memory size need be provided in the flash memory for the (second) memory area. The RAM also need only provide small memory capacities for the application, since only the data to be applied need be read into the RAM, while the rest of the operating data, which remain unchanged, can be read from the appropriate memory area of the nonvolatile memory for current component control. According to the invention, the control unit data record in the nonvolatile memory (in particular, flash memory, but also EEPROM or the like) can have various configurations, with the option of dynamically transferring individual data segments having a size of, by way of example, 1 kilobyte to the RAM area for online application, and storing them back in the nonvolatile memory within the control unit after application.
In accordance with an added mode of the invention, there is the step of writing all the control data present in the second memory area to the first memory area.
In accordance with an additional mode of the invention, there is the step of writing back the updated control data record to a same point in the first memory area from which the control data record had been read before it was applied/updated.
In accordance with another mode of the invention, there is the step of transferring the control data of the control data record located in the second memory area which are to be applied/updated in sections to the further memory. The control data are updated there and are stored back, and this operation is repeated for the next control data record sections located in the second memory area which are to be applied/updated.
In accordance with a further mode of the invention, there is the step of setting pointers that point to addresses of the control data record to be applied/updated in the second memory area and in the further memory, respectively.
In accordance with another added mode of the invention, there is the step of providing a further, nonvolatile memory to be accessed for selecting the control data record and outputting positions at which the control data record is located in the first memory area.
In accordance with another additional mode of the invention, there is the step of reprogramming the electronic motor vehicle control unit such that it accesses the positions of the updated control data record located in the first memory area irrespective of a content of the further, nonvolatile memory when the application is terminated.
In accordance with yet another mode of the invention, there is the step of embodying the further memory as a random access memory.
In accordance with an added mode of the invention, during the accessing step, there is the further step of accessing further control data stored in the second memory area and updating the further control data resulting in further updated control data. The further updated control data is used for controlling the motor vehicle component that is to be controlled.
In accordance with a further mode of the invention, there is the step of embodying the nonvolatile memory as a flash memory.
In accordance with another mode of the invention, there is the step of writing back the updated control data present in the second memory to the first memory area.
In accordance with a concomitant mode of the invention, during the reprogramming step, there is the step of permanently storing access addresses of the updated control data record located in the first memory area.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a method for applying control data for an electronic motor vehicle control unit, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.